Hedge trimmers are power tools for general garden use with an axially reciprocating blade comprising a plurality of teeth disposed adjacent a stationary blade, the teeth of the stationary blade providing a reaction force for the teeth of the reciprocating blade.
Most hedge trimmers are provided with two handles for the user to grip. This is generally for two reasons. Firstly, a hedge trimmer is easier to manipulate when held with both hands than when held with one hand. This provides the user with greater control over the hedge trimmer and therefore facilitates more accurate cutting. Secondly, a two handed grip is a safety feature. It is significantly easier to lose control of a hedge trimmer when holding it with one hand, and therefore a two handed grip allows much safer use of the hedge trimmer.
For this reason, hedge trimmers are generally provided with a dual switching mechanism where independent switches are provided on both the front and the rear handles, and in order to activate the hedge trimmer, both switches must be depressed simultaneously.
An example of a dual switching mechanism for a hedge trimmer is described in EP 0214455. This document describes a hedge trimmer with a front handle having three independent switches, and a rear handle having a single switch. On actuation of any one of the front switches, a wire running through the front handle is tensioned, causing a pin to be removed from an electrical contact, and thus the contact to be closed. The rear switch abuts an electrical contact, and therefore when the rear switch is depressed, the contact closes. With both electrical contacts closed, the hedge trimmer activates.
The hedge trimmer described in EP0214455 suffers from the drawback that as two independent switching mechanisms are required to activate the hedge trimmer, there are a large number of components required, and therefore there is greater scope for breakages. This hedge trimmer also suffers from the drawback that as there are a substantial amount of electrical components and wiring required, this type of hedge trimmer is therefore costly to produce.
Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art.